Stribild was well-tolerated and associated with favorable immunovirologic outcomes in ART-naive patients with HIV-2 in West Africa, according to recent data.
“For too long, outcomes of HIV-2–infected patients on ART in West Africa and other locales have been suboptimal, and new therapeutic options are needed,” Geoffrey S. Gottlieb, MD, PhD, associate professor in the departments of medicine and global health at the University of Seattle, and colleagues wrote in Clinical Infectious Diseases. “Our findings support the use of integrase inhibitor-based regimens for HIV-2 treatment. Efforts to make them available in HIV-2–endemic areas should be an urgent priority.”
According to the researchers, approximately 1 to 2 million people are infected with HIV-2 worldwide. The virus is endemic in West Africa. Compared with HIV-1, HIV-2 is associated with a longer asymptomatic disease stage, lower plasma viral loads, slower decline in CD4 cell counts, and lower rates of mortality, genital shedding and transmission. Still, many patients with HIV-2 progress to AIDS and may benefit from ART, Gottlieb and colleagues reported.
Despite its discovery more than 3 decades ago, there are no treatments approved for HIV-2 in the United States or Europe. Little is known about the safety and efficacy of ART in patients with the virus, but Gottlieb and colleagues said there is an “urgent need” for safe and effective drugs. Anecdotal evidence from case reports and clinical series suggest ART regimens containing integrase inhibitors (INIs) are potentially effective. To confirm this finding, the researchers conducted the first clinical trial investigating the use of a once-daily, single-tablet regimen of Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate, Gilead Sciences; E/C/F/TDF) in ART-naive patients. The trial enrolled 30 patients (80% women) from Senegal, West Africa with a median age of 49 years and CD4 count of 408 cells/mm³. Among the participants, seven had WHO-defined stage 3 or 4 disease upon enrollment, and 73% had detectable HIV-2 RNA.
Treatment acceptability was high, with 96.7% of patients completing the 48-week follow-up period, according to the researchers. Virologic control and suppression was maintained or achieved in 93.3% of participants, and median CD4 count increased 161 cells/mm³, regardless of viral load status.
A safety analysis revealed that E/C/F/TDF was generally well-tolerated. No adverse events were related to the study treatment. However, one patient developed multidrug-resistant HIV with reverse transcriptase and integrase mutations between weeks 36 and 48 of treatment.
“Our findings, together with the forthcoming results from three other trials of first-line, INI-based ART for HIV-2, will hopefully help define evidence-based guidelines for [the] management of this oft-neglected infection,” the researchers concluded. “In addition, our data suggest that there is a potential benefit in treating HIV-2–infected individuals with either low or undetectable viral loads, as well as those with CD4 counts about 500 cells/mm³. Moreover, extrapolating from the wealth of data from HIV-1 infection, it would not be unreasonable to consider treatment for HIV-2 as soon as individuals are diagnosed and ready to start ART.”
By Stephanie Viguers